Metamath Proof Explorer


Theorem fsetfcdm

Description: The class of functions with a given domain and a given codomain is mapped, through evaluation at a point of the domain, into the codomain. (Contributed by AV, 15-Sep-2024)

Ref Expression
Hypotheses fsetfocdm.f F = f | f : A B
fsetfocdm.s S = g F g X
Assertion fsetfcdm X A S : F B

Proof

Step Hyp Ref Expression
1 fsetfocdm.f F = f | f : A B
2 fsetfocdm.s S = g F g X
3 vex g V
4 feq1 f = g f : A B g : A B
5 3 4 1 elab2 g F g : A B
6 ffvelrn g : A B X A g X B
7 6 expcom X A g : A B g X B
8 5 7 syl5bi X A g F g X B
9 8 imp X A g F g X B
10 9 2 fmptd X A S : F B